DC-DC converters may convert a source of direct current from one voltage level to another.
Certain DC-DC converters convert one DC voltage level to another by storing the input energy temporarily and then releasing that energy to the output at a different voltage. The storage may be in either magnetic field storage components (inductors, transformers) or electric field storage components (capacitors). By adjusting the duty cycle of the charging voltage (the ratio of on/off time), the amount of power transferred can be controlled. Such conversion may be more power efficient (often 75% to 98%) than linear voltage regulation (which dissipates unwanted power as heat). This level of efficiency may be beneficial to increasing the run time of battery operated devices.
The efficiency of some DC-DC converters has increased in recent decades due to the use of power field effect transistors, which are able to switch at high frequencies and more efficiently than power bipolar transistors, which may incur greater switching losses and require complicated drive circuits.
Battery (or other alternatively) powered automotive vehicles may include a converter arranged to increase a voltage output by a battery and/or decrease a voltage to be input to the battery.